124 



CHAPTER XXXI. 



OF THE TURBO. GENUS XXVIII. 



TURBO. 



" Animal a Lima.r. Shell univalve, spiral, solid ; aperture contracted, 

 orbicular, entire." — Linn. 



1 HE essential character of this genus consists in the aperture 

 or mouth being round, and, like the Trochiis, without any 

 hollow or canal on the margin. 



If this were strictly adhered to, and no shell placed here but 

 wliat agreed perfectly with the definition, there would be 

 no great difficulty in distinguishing this genus ; but many 

 shells are called Turbines by Linnaeus, Gmelin, and others, the 

 moviths of wliich are not exactly round. In T. Delpkinus, 

 Lincina, petholatus, Chrysostotmis, and others, the mouth is 

 round ; but in littoreus, personatiis, Pullus, and many more, 

 it is as it were dra^vn or extended into an angle towards the 

 spire, which form is also seen in several of the Trochi, as 

 Trochus JLabio, &c. : and in many Helices, as Helix vivi- 

 liara, tentaculata, &c. Turbo Fusus is said by Gmelin to be 

 lunate, from which we should expect it to be a Helix. T. tri- 

 dens he describes with the aperture curved, nautileus with it 

 long, sulcatus with it nearly square, and helicoides with it 

 triangular. T. Uva, bidcns (^pl. E.f. 101 and 103), and several 



